Input
The first line of the input contains a single integer n (1≤n≤103) — the side of the board....The i-th of the next n lines of the input contains 2n integers x1,y1,x2,y2,…,xn,yn, where (xj,yj) (1≤...line containing INVALID....In the i-th of the next n lines, print the string of n characters, corresponding to the characters in...flag)
{
cout INVALID" << endl;
return 0;